RE: Database Access Path Question

["Smith, Nelson" <NSmith@xxxxxxxxxxx>]

That's what I thought, Paul.   However, if I put the select field in front
of the keys (as the first key) and then did READE on the data to be selected
plus the normal keys, wouldn't I get the same benefit as DYNSLT without the
run time hit?

> -----Original Message-----
> From: Paul Tuohy [SMTP:tuohyp@attglobal.net]
> Sent: Thursday, February 06, 2003 11:43 AM
> To:   Midrange Systems Technical Discussion
> Subject:      Re: Database Access Path Question
> 
> Nelson,
> 
> If the two logicals have the same keys and select field, but select on 
> different data in that select field they will NOT use the same access 
> path. The access paths will only contain the keys of the records that 
> satisfy the selection criteria.
> 
> If you specify DYNSLT, then the selection criteria is ignored (in 
> regards to the access paths), so the access path will be shared between 
> the two logicals (since the key definition is identical. You will take 
> the selection "hit" at run time, when you use the access path.
> 
> HTH
> 
> Paul Tuohy
> 
> Smith, Nelson wrote:
> > The DYNSLT discussion is interesting, but doesn't directly address my
> > original question:
> > 
> > If two logicals have the same keys and select field, but select on
> different
> > data in that select field, will they use the same access path, part of
> the
> > access path, or not at all? 
> > 
> > 
> >>-----Original Message-----
> >>From:       Steve Richter [SMTP:srichter@autocoder.com]
> >>Sent:       Thursday, February 06, 2003 10:35 AM
> >>To: Midrange Systems Technical Discussion
> >>Subject:    RE: Database Access Path Question
> >>
> >>It depends on how many records meet the selection criteria. One factor
> >>that
> >>will always favor dynslt is that data mgmt can select records much
> faster
> >>than rpg code can.
> >>
> >>accpth(*rebld or *dly) is another option.  Create standalone logicals
> w/o
> >>dynslt.  If they are used once a week in batch or if conditions permit
> in
> >>an
> >>online appl, tell the system to *DLY accpth maint or *REBLD the accpth
> >>with
> >>the file is opened.
> >>
> >>Steve
> >>
> >>-----Original Message-----
> >>From: midrange-l-bounces@midrange.com
> >>[mailto:midrange-l-bounces@midrange.com]On Behalf Of David Dunfield
> >>Sent: Thursday, February 06, 2003 10:12 AM
> >>To: Midrange Systems Technical Discussion
> >>Subject: RE: Database Access Path Question
> >>
> >>
> >>DYNSLT may be an option, but we have experienced less than great
> >>results using dynslt in reading records. It does work, but it still
> >>reads all records in access path to select only those DYNSLT.
> >>
> >>
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> > 
> > 
> >
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